Pliable grommets are used to provide weatherproof conduits for electrical and/or pneumatic lines extending between, for example, an automobile body structure and a hinged door attached to the body structure.
The typical grommet is a tubular body made of soft pliable material such as EPDM rubber and having integral enlarged end portions. Hard plastic retainers are placed into the enlarged end portions to provide a snap-in installation and retention function relative to a pre-formed aperture in the panel through which the service line protected by the grommet extends. The retainer is usually frame-shaped and has barbs to engage the edge of the aperture and hold the grommet against the body panel to provide a seal.
A problem associated with a structure of the type described above arises out of the fact that there is no easy way to confirm the fact that the retainer is correctly installed into the grommet end portion. This can give rise to construction delays and/or faulty installations.
Visual installation confirmation can be provided by forming a number of holes in the grommet wall structure and to provide projecting elements on the outer edge of the retainer in locations which are matched with the holes so that the projections extend through the holes when the retainer is properly installed. While this approach provides retainer installation verification, the presence of the holes in the grommet tends to compromise the weatherproof quality of the grommet in that they increase the possibility of moisture intrusion.